Self-administration of medicinal eye drops tends to be both annoying and awkward. Typically, a person's head must first be tilted backward until the person is looking straight above. This creates a maximal target area of the person's eye and tends to help retain the falling eye drop into the person's eye. Then, while maintaining the person's head in this extended position, the person must invert a conventional eye dropper bottle over the eye and simultaneously attempt to precisely position the tip of the dropper directly over the target eye area while holding their eyelids open with the other hand. Once properly positioned, the person must then squeeze the reservoir of the dropper bottle to dispense the medicinal liquid, without moving either their head or the dropper.
Several factors complicate this conventional eye drop installation procedure. First, it is physically difficult for many persons, particularly when self-administering the eye drops, to both position and maintain their heads in a tilted back orientation. Second, many persons have difficulty raising their arms up over their heads due to limitation of motion of the wrist or shoulder, thus making it difficult for such persons to accurately position a conventional eye dropper bottle over the targeted eye area. Third, there are some individuals who may get vertigo or dizziness when placing their head in a backward position while instilling drops into their eyes.
One logical solution to the difficulty of raising a dropper bottle over the person's head is to configure the eye dropper bottle in an upright manner with a tip having an opening for release of drops located above a reservoir. One such prior art eye dropper bottle is described in the patent to Podell (U.S. Pat. No. 3,756,478). Some bottles deliver fluid in such an upright manner by utilizing a tube that extends from the reservoir where the liquid is stored to an outlet above. Such an upright orientation has many problems, however. First, small pockets of air are trapped between drops of liquid within the tube of such a conventional upright dropper, and when the reservoir of the dropper is squeezed, a mixture of air and medicinal liquid will result. The air/liquid droplet often will not release from the tip of the dropper in a consistent fashion. Also, the air to liquid proportions of the droplet vary so widely that it is not accurately quantifiable, so the person is not able to determine if the drop was enough of a dosage or if further doses are needed.
Also, if the tip of the dropper bottle is not held in a substantially inverted position with the tip directed downward, an eye drop may adhere along the exterior of the tip away from the opening of the tip. Hence, the drop will be released at a point spaced away from the opening of the tip of the dropper and tend to miss the person's eye altogether. Often a drop will adhere to the tip of the dropper and will not release until a second drop is expressed from the bottle. This causes considerable waste as the drop(s) or a portion of them never release from the tip.
All of the above factors further amplify the difficulty of self-administering an eye drop. Hence, a person may be substantially impeded from accurately and reliably self-administering an eye drop solution.
Due to the inherent inaccuracy associated with the conventional process of instilling eye drops, a person may instill either more or less than the prescribed dosage. For example, recognizing that a portion of the intended dosage has missed its target, a person may elect to administer a substantially increased dosage based upon his subjective assessment of the portion of each droplet that actually reached or missed its intended target area. If too much medicinal liquid is instilled, the overdose could prove detrimental to the person. Additionally, overdosing and waste from inaccuracy may cause the prescription volume to be prematurely consumed, thereby shortening the duration of the treatment and potentially failing to adequately treat the condition for which the medicine was intended. It also greatly adds to the expense of treating ocular conditions, especially chronic situations such as glaucoma. Correspondingly, if the person fails to instill the required dosage in his eye, the treatment may be inadequate.
The prior art is replete with numerous attempts to provide devices to more easily instill medicinal liquids in a person's eye. The bulk of the attempted methods still require that the head be tilted back while simultaneously dispensing the liquid eye medicine. Various devices described in the prior art incorporate eye cups which are placed fully over at least one eye before dispensing the medicinal liquid. These devices are configured to wash the eye, rather than deliver drops of medication.
Today, standard dropper bottles consist of a small deformable reservoir and a conically-shaped tip. These standard dropper bottles must be inverted over a person's eye during use. Many manufacturers market both over-the-counter and prescription eye drop solutions which are dispensed from these conventional eye dropper bottles.
A variation of standard dropper bottles is described by Menchel et al. in U.S. Pat. No. 5,069,675. The Menchel patent discloses an applicator for liquid eye preparations which includes a resilient container and associated head similar to those described above. The Menchel dropper bottle differs only in that a different type of cap is placed over the head of the dropper. Menchel's cap includes a laterally protruding spout which is rested against a person's lower eyelid while the person self-administers the medicinal liquid into his eye. However, Menchel's dropper must also still be inverted, with the reservoir of medicinal liquid positioned above the spout, to allow instillation of the eye drops. Further, placing the tip of the laterally protruding spout of Menchel's invention immediately adjacent the surface of the eye creates a potentially hazardous circumstance. Any inadvertent movement could cause the tip to jab the person's eye, causing some damage or at least, temporary irritation. Additionally, resting the laterally protruding spout against a person's lower eyelid could contaminate the spout and the remaining medicinal solution contained within the reservoir of the dropper.
Accordingly, a need exists for a dropper for medicinal eye liquid which can be used with the dropper in an upright position, having its reservoir of medicinal liquid positioned below its tip, and a person's head also oriented in an upright position. A corresponding need exists for such an eye dropper where no portion of the dropper tip touches a person's eyes or eyelids while being administered. A further corresponding need exists for such an eye dropper where the tip of the dropper can be easily and precisely positioned by a person over his eye to maximize accuracy during instillation of the eye drops. This can be accomplished best by the use of a mirror where both the eye and the tip of the bottle are well visualized. Finally, a need exists for such an eye dropper capable of discharging eye drops of substantially equivalent volume to ensure accurate dosage of the medicinal liquid is administered to a patient's eye.